The Samoans beat Vanuatu by eight wickets yesterday morning to make it four straight wins in Port Vila, with captain Regina Lili'i top-scoring with 37 not out as they overhauled the hosts total of 58 with five overs to spare.
Lili'i has scored a tournament-best 149 runs and is yet to be dismissed in four games, while Lagi Telea snared 3 for 9 from four overs with the ball.
Defending champions Papua New Guinea also maintained their unbeaten start in thrashing Japan by 10 wickets in the afternoon.
The Lewas restricted Japan to a miserly total of 37 all out in 19.3 overs, with captain Kaia Arua awarded player of the match after returning impressive figures of 5 for 7 from four overs.
Openers Sibona Jimmy and Tanya Ruma then cruised to their victory target in the seventh over to regain top spot in the overall standings courtesy of a superior net run rate.
In other results, Japan notched their first win of the tournament against Fiji while Nasimana Navaika top-scored as Vanuatu beat Indonesia by four wickets.
Samoa and PNG will square off in the final match of the tournament this afternoon, with the winner advancing to the ICC Women's T20 World Cup Qualifier in Scotland later this year as well as next year's 2021 Women's World Cup Qualifier.